Sunscreen with high SPF needed at high altitudes

MIAMI BEACH, FL (Reuters Health) - Golfers playing in Vail, Colorado, at 2500 meters (roughly 8200 feet) above sea level, got significantly more burn protection from sunscreen with a sun protection factor (SPF) of 70+ compared to one with an SPF of 15.

"The SPF 70+ formulation was...very effective in protecting skin from sunburns under extreme ultraviolet light and real sporting conditions," study chief Dr. Darrell Rigel from New York University Medical Center said at AAD 2010, the 68th annual meeting of the American Academy of Dermatology.

"You have to be extra careful at protecting yourself at high altitudes," Rigel told Reuters Health. "People don't realize how much additional sun you get at higher altitudes. It's anywhere from an 8 percent to a 10 percent increase for every thousand feet of elevation. In the summertime, you can get anywhere from 40 percent to 50 percent greater sun intensity than at sea level."

In the study, 43 people playing golf for an average of 4.5 hours each applied the sunscreen themselves. Twenty-one golfers applied the SPF 70+ sport sunscreen over the entire face before they went out to play golf, and then reapplied the sunscreen about half way through their golf game - about 2 hours into UV exposure - to only one half of the face.

The other 22 golfers applied the SPF 70+ sunscreen to one side of the face and a regular SPF 15 sunscreen to the other side of the face before they went out to play golf.

The researchers monitored the UV conditions to ensure that golfers would have been expected to burn without sunscreen. At the end of the golf games, a dermatologist analyzed the golfers' faces.

Rigel reported that golfers who started out with the SPF 70+ sunscreen on their entire face and then reapplied it to half the face two hours later had no skin reddening at the end of the 4.5 hours, and none of the golfers who used the SPF 70 formulation complained of sunburn.

In comparison, a significant 7 of 22 golfers who applied SPF 15 to half the face had noticeable skin reddening on that side.

Rigel, who tests sunscreen efficacy for a variety of manufacturers, is against the proposal by the U.S. Food and Drug Administration to limit the SPF of sunscreens to 50.

In a study published last month in the Journal of the American Academy of Dermatology, Rigel and his colleagues reported similar results with ski instructors in Vail, who applied two different sunscreens - one with an SPF of 50 and the other with an SPF of 85 - to different sides of their face. The SPF 50 sunscreen was not enough to protect them from sunburn.

"They put the sunscreen on in the morning, before they went out and skied an average of 5 hours a day and when we evaluated them the next morning, the ones who used the SPF 50 formulation were burned," he said.

"We sent the results to the FDA because they are considering putting a cap on high SPF. They've been thinking of doing this for 2 years now, but they haven't made their final ruling."

Also, Rigel said, "People do not typically apply sunscreen in the proper amount, and only use anywhere from 20 percent to 50 percent of the recommended amount. So they are not getting the protection they think they are getting."

Higher SPF formulations also tend to last longer and be more sensitive, he added.

Finally, "as we showed in the study, an SPF of 50 is not always enough. So if they put a cap on 50, there will be no incentive for sunscreen manufacturers to make a better sunscreen. And that could be the most important reason. Why would you not want the opportunity to have a better sunscreen?"